Train control



Oct. 30, 1928. 1,689,229

c. s. BUSHNELL mm: comm,

Filed June 28, 1924 MM 2 .T'ToRNEY.

all

Patented Get. 30, 1928.

CHARLES- S. BUSHNELL, 0F BOGH'ESTER, 'NEVI YCRK, ASSIGNO'R T 0 GENERALEAIL- WAY SIGNAL COIYIEZKNY, OF ROCHESTER, NEVT YORK.

TRAIN: CONTROL.

Application filed June 28, 1924. SerialNo. 723,047.

This invention relates to train control systems of the three-position orpolyphase continuous inductive type, and more part-icu larly to meansfor economically increasing 1 the eificiency of the inductwe influencere ceiving apparatus used for detecting line phase current in the track.rails. I

Generally speaking, a continuous inductive'train control system of thethree-position or polyphase type consists of athreeposition. relayconnected to suitable amplifying devices on. the C211,-IOI3 which thecurrent in one'of the phases of this relay is inductively detected fromcurrent flowingin opposite directions in the two rails in front oftrain. corresponding to the usual track circuit current, and. in whichthe current in the other phase flows in response to current detectedflowing in the two trackrails in multiple, both of these currents beingamplified. by suitable amplifying means; for various reasons, possiblybecause a single phase. or single element relayfor detecting line phasecurrent is employed in addition to the polyphase relay, or because thetrack phase current is cut down to a lower value or a less number ofstages of amplifying apparatus are employed, it may be considereddesirable to pick up inductively as much potential due to linephase-current flowing in the two track rails in multiple as possible;and in accordance with the present invention it isproposed to employfourinfluence receiving coils for detecting. line phase current and twoinfluence receiving coils for detecting track phase current. More.specifically is proposed tohavetwo receiving ele- .ments at the front ofthe locomotive, be-

tween the locomotive and tender and at the rear of the tenderrespectively, of: which the middle pair of coils are always connectedcumulatively for currents flowing. in the same direction in the twotrack rails, the rear pair'of elements are-similarly connected and inseries with the middle pair and in which the front pair of elements areconnect'cd so that voltagesinduced therein. due to track phase currentflowing in one direction in one rail and the other direction in theother rail. are cumulative, regardless of whether the engine 7 andtender unit runs pilot or tender first. v v Other ob ects, purposes andcharacteristic features of the invention will appear asv the descriptionprogresses.

In describingv the invention in detail. reference will be had. to thedrawing which illustrates conventionally and in a diagrammatic mannerthe car carried and trackway apparatus of one embodiment of the presentinvention, a V

The trackway apparatus is illustrative ofa typical three-position,continuous inductive train control system and! only a very briefdescription thereof is deemed necessary. The usual track ra ls 1 havebeen shown divided into blocks by insulating. joints 2, the block I andthe adjacent ends of two other blocks .H and J being shown. Since thevarious blocks are the same, like parts of each block are designated bylike reference characters having distinctive exponents. At the entranceend of-theblock I is shown a track relay 3, of the two element typehaving one of its coilsv connected across the track rails and havingits. other coil connected to the secondary winding oil a trans former4:. receiving energy from the line wires- 5 connected to a suitablevsource'bf alternating current. The exit end of the block I is providedwith theusual track: current source comprising a transformer 6 havingits, secondary winding connected across the track. rails throughv theusual impedance P I. spend to the elements making up the usual trackcircuit whereby, current is-adapted to flow down: onefrail tl irouglitherelay 3 and This relay and trackway source correthat if both of thesecurrents are'detected.

and applied to the coils of a polyphase relay of the inductiontype onthe car, such relay may be actuated. In the arrangementshown thislinephase current is caused to flow in the two rails in multiple by havingwires um v tapped to the middle points ofg balancing resistanceslO, 11,12and 13. The first section of the bloclr I is normally energized byline phase current having a normal phase relation'with respect to thetraclrway current through a circuit which may be tracedas followsbeginning at the transformer 4 wires and 16 contact 17 of the trackrelay 3 wire 18, balancing resistance 10 through the first section ofthe two track rails in mutiple to the balancing resistance 11, wires 19and 20 front contact 21 wires 22 and 23 back to the transformer 4 Itwill be noted that deene'rgization of the track relay 3 completes thesame circuit in a manner so that the current flow therein is reversed.The second section of the block, extending from the point B to the exitend thereof, is under clear traffic con ditions energized by currenthaving a normal phase relation with respect to the trackway current, andflowing in the following circuit:beginning at'the transformer 25, wire26 front contact 27 wire 28, balancing resistance 13, the two rails inmultiple of the second section of the block I, balancing resistance 12,wire 29, back to the secondary winding of the transformer 25. It shouldbe oted that the line phase current of this second section of the blockI is cut off when the block J in advance thereof is occupied and thetrack relay 3 assumes its deenergized position.

From the foregoing it will be noted that a train equipped with suitablecar carried apparatus is adapted to detect both line phase and trackphase currenthaving a normal phase relation when moving in the block Iwhen both'the block I and the block J next in advance thereof areunoccupied, that such a train is adapted to pick up line phase and trackphase current having a reverse relative phase relation when movingbetween the entrance of the block I and the point B when the next blockin advance is occupied but'can pick up track phase current only beyondthe point B under this condition, and that a train so equipped enteringthe blocl; I when'this block is already occupied by another train aheadcan detect line phase current only. In other words, a train equippedwith a polyphase relay and suitable detecting and amplifying means wouldhave its relay energized in a normal position when it enters a clearblock, would have its relay assume thereverse position when moving'in acaution block between the entrance thereof and the point B and have itsrelay assume the deenergized position when moving beyond the point B ina caution block or when moving in an occupied block.

Referrin to the drawing in which one embodiment o the car-carriedapparatus of the present invention has been conventionally illustrated,the usual'engine has been shown .bythe wheels and axle 31 and the tenderOne end of the rod 33 is slidably mounted in a support 38 and the otherend is pivotally connected to the free end of a clutch arm 40 having itsother end frictionally connected to a suitable shaft driven from thewheels of the vehicle; the shaft in practice would' preferably belocated on top of the tender. In the arrangement shown the frictionalconnection of this arm 40 to the shaft 41 comprises a brake shoe 42having an extending rod 42 which is slidably mounted in a lug 43. Thisbrake shoe 42 is lined by suitable friction material 48 and is springpressed against this shaft 41 by a compression spring 49. The particularmechanism shown for operating the switch rod 43 in one direction or theother depending on the direction the tender is moving is merely aconventional illustration for showing how the various switch blades maybe thrown in one direction or the other depending on the direction inwhich the train is traveling and in practice will take a more elaborateform to assure proper functioning throughout a long period of use.

At the front of the engine and at the rear of the tender are locatedcores 52 and 53 each having depending legs terminating in enlarged polepieces serving as flux collectors. coils 54 and 55 and on the core 53are con tained similar coils 56 and 57. Between the engine and tenderand suitably mounted on the engine is contained a core 58 having onlytwo depending legs and having coils 59 and 60 wound thereon in a mannerso that voltages induced therein due to currents flowing in the samedirection in both rails are cumulative.

In order to illustrate how these various coils may be connected toamplifying devices which have their output circuits connected to thewinding of a relay, a main relay MR having windings 62 and 63 has beenillustrated. The winding 62 is connected to the output circuit of atrack' phase amplifying device TA and the winding 63 of this relay MB isconnected to the output circuit of the line phase amplifying device LA.These amplifying devices TA and LA include suitable vacuum tubeamplifiers or audions of special construction so as to withstand jarsand vibrations, a suitable source of energy, tuning apparatus and thelike, and since the present invention is not directed toward anyparticular type of amplifying apparatus these amplifying devices havebeen shown conventionally.

For the purpose of illustrating how the 'relay MR may be used toindicate traffic conditions ahead, suitable cab signals G, Y and B havebeen illustrated which are energized under clear, caution and dangertraflic conditions, respectively, as is obvious from the circuits forenergizing these cab signals On the core 52 are contained two liltlnesegaae by the battery'65 illustrated, the relay MR being shown in its:normal clear trafli'c'condition. Also, to show how the relay mayrestrict the movement of the train in a certain manner when thisrel'ayis energized into the reversed position a: normally energized traincontrol device K energized bythe battery 66 has been shown," this deviceK when-'deenergized may control the train in any desired manner, thatis, may set up restrictive speed limits which are gradually changed withthe progress of the vehicle, may apply the brakes if the train exceedsacertain low speed limit unless the brakes have been manually applied-bythe engineer, on the like; and a similar device K which is energizedunder both clear and caution trafflc conditions but is deenergized underdanger trafiic conditions: is provided for properly controlling thetrain upon entering or when moving in adanger block. This device K 3maybe of construction similar to that of the device K exceptthat itrestricts the movement of the train more than does the device K.

lVhen the train is moving from left to right asindicated by the arrow,the coils on core 52 are connected to the-track amplifying device TA; ina mannersothat voltages ind'uced in: the coils 54 and 55 due to currentsflowing in opposite directions in the track rails are cumulative throughthe following circuit :--beginning'at the input wire 700f the amplifyingdevice TA, wire 71, contact blade d6, wire 7 2', coil 55, wire 73, blade47',

wires T l 75 and 76, contact blade 1 44:, wire 77, coil 54-, wire 78,contact blade 4-5, wire v'I'Qback to the other input wire 8010f theamplifying device From tracingthis circuit it willbe noted' that thecoils 5 l-and of the receivingelementincluding; core 7 52 were tracedin: opposite directions. as iii-.-

dicated by the solid arrowslso that the volt--- agesinduced in thesecoils due to track phasecurrent" are cumulative. pressing potentials onthe line'amplifying device LAv when the vehicle is moving-from: left toright may be traced as follows beginning at the input lead 81 oftheamplil tying device LA, wire 82,. switch blade 35, wire 83', coil 56 inthe direction as indicatedby the solid arrow, wire 84, blade 34,. wires85, 86 and 87, switch blade 86, wire 88, coil157 in the direction. asindicated by the solid: arrow, wire 89, switch blade 37', wire 90, coil:59 in the direction as indicated by the solid; arrow, wire 91,.coil 60:in. the directionzas indicated by the solid arrow to the wire 92 of theamplifying device LA; 'By observing the direction indicated by the solidarrows shown adjacent to coils 56, 57," 59' and 60 it will be noted thatthe voltages induced in these four coils due to current flowing in thesame direction in both rails cumula-,

tive. With the currents flowing in these The circuit for im"-- 1circuits asindicated by' th'e solid arrows the relay M R will assume itsnormal energized position: as shown inxthe drawing and if ither thetrack phase or line phasecircuit isv reversed this relay M R- assumesits reversed; position.

If'now the engine and tenderunit is turned end forend and moves fromleft to right, the coils56 andf 57 will be connected to the am--plifying device TAL to detect track phase current and the coils 5 1, 55,59 and 60- will be connected iir-seriesto detect line phase currentandwilli be connected to the amplifying device Lin, this by'reason'= of thereversal ot the multipl'e bladereversing switch shown. It isconsideredunnecessary to trace the cir cuits specified when these switchesassumethe reversed dot-ted position since these circuits. mayice-readily traced,- but" it maybe pointed out that with theengine-andtender unit moving" tender first thevarious pairs ofcoilsare-connected in series asindicated by the dotted arrows.

Having thus shown and described one specific embodiment of theinventionitis desired to be understood. that the specific arrangementshown has been: disclosed to illustrate the nature offltheinventfionrather ducti ve type comprising-,a pair of coils lo'- cated in inductiverelation to thetrack rails connected: to cumulatively detect currents vflowing" in. opposite directions in the trackrails ahead of a: car, twopairshof coils eaclr pair of which is. connected tocumulativeIy detectcurrentsflowing in the same direction in v the two: track: rails under"the .ca'r, ampliphase relay'liavin'g'two:windings, an amplifying deviceconnected to each of said windmgs, three pairs ofinductive influencedetecting coils, and means for connecting the leading pair of coils tocumulatively detect currents flowing in opposite directions in the tworails ahead of the train to one of said amplifying device connected toeach of said windings, three pairs of inductive influence detectingcoils, and means automatically operated, dependent upon the direction inwhich the train is IDOVIDO, for connecting the leading pair of coils ina circuit to cumulatively collect energy in response to current flowingin opposite directions in the two rails ahead of the train and forconnecting the other two pairs of coils to cumulatively collect energyfrom current flowing in the same direction in the two track rails inmult-iple, regardless of the direction in which the train is moving.

4. In an automatic train control system, the combination of trackwaymeans for causing currents to flow along the trackway in two distinctivecircuits, one of which includes the two rails ahead of the train inseries and the other of which includes the two track rails in multiple,and of carcarried apparatus including three pairs of inductive influencereceiving coils, each pair of which is disposed in inductive relationwith the two trackrails, and means controlled in response tothedirection of move-'- ment of the train for connecting the leadingpair of coils so that voltages induced therein due to currents flowingin opposite directions "in the rails are cumulative and for connectingthe remaining two pairs of coils in series in a manner so that voltagesinduced in these coils due to currents flowing in the two rails inthesame direction are cumulative.

5. In an automatic train control system, the combination of trackwaymeans for causing currents to flow along the trackway in two distinctivecircuits one of which in cludes the two track rails ahead of the trainin series and the other of which includes the two track rails inmultiple, and of car-carried apparatus including three pairs ofinductive influence receiving coils, each pair of which is disposed ininductive relation with respect to thetwo track rails, and meansincluding a slip friction clutch of which one element is driven from thewheels of the vehicle and the other element is adapted to move into.

one or theother extremeposition, contacts of which includes'the twotrack rails ahead, of the car in series and the other of which.

includes the two track rails under the car in multiple, car-carriedapparatus including two pairs of inductive influence receiving coils,one pair of which is located in front of the firstaxle of the car, andconnected to cumulatively detect currents flowing in opposite directionsin the rails and the other pair of which-is located behind the last axleof the car and connected to cumulatively detect currents flowing in thesame direction in the two rails, and means operated by an axle of thecar and efl'ected to make the necessary changes in the connections ofthe pairs of coils to detect such currents when the car is turned endfor end and is moved along the track in the same direction.

7. In an automatic train control system, the combination of trackwaymeans for causing alternating currents supplied from a transmission lineto flow along the trackway in two distinctive circuits, one circuitofwhich includes the two track rails ahead of the car in series and theother of which includes the two track rails under the car in multiple,car-carried apparatus Including two pairs of inductive influencereceiving coils, one pair of which is located in front of the first aXleof the car and connected to cumulatively detect currents flowing inopposite directions in the rails and the other pair of which is locatedbehind the last axle of the car and connected to cumulatively detectcurrentsflowing in the same direction in the two rails, and meansincluding a slip-friction clutch operated by an axle of the car andwhich renders the necessary changes in the connections effective todetect such currents when'the car is turned end for end and is moved inthe same direction along the track.

In testimony whereof I aflix my signature.

CHARLES s. BUSHNELL.

